简介:Objective:Noninvasivediffusion-weightedmagneticresonanceimaging(DWI)isawell-studiedMRimagingtechniqueforquantifyingwaterdiffusionespeciallyintumorarea.Thecorrelationbetweenapparentdiffusioncoefficient(ADC)valueandapoptosisorproliferationisnotclearbynow.ThisstudyaimedtoinvestigatewhetherDWI-ADCvaluecouldbeusedasanimagingmarkerrelatedwithpathologicindexesoftumors.Methods:Atotalof30Balb/cmicewithHT29colorectalcarcinomaweresubjectedtoDWIandhistologicanalysis.ThepercentageofADCchangesandtheapoptoticandproliferatingindexeswerecalculatedatpredefinedtimepoints.Kolmogorov-SmirnovdistanceswereconsideredtodeterminewhetherthepercentageofADCchanges,andtheapoptoticandproliferatingindexeswerenormallydistributed.Anindependent-samplest-testwasusedtoanalyzethedifferencebetweenapoptoticandproliferatingindexesinthetwogroups.Results:Therewasastatisticallysignificantdifferenceinproliferatingindexbetweentheradiotherapyandcontrolgroups(meanproliferatingindex:49.27%vs.83.09%),andtherewasastatisticallysignificantdifferenceinapoptoticindexbetweenthetwogroups(meanapoptoticindex:37.7%vs.2.71%).AsignificantpositivecorrelationwasfoundbetweenthepercentageofADCchangesoftheviabletissueandapoptoticindex.Pearson'scorrelationcoefficientwas0.655(P=0.015).AsignificantnegativecorrelationwasfoundbetweenthepercentageofADCchangesoftheviabletissueandki-67proliferationindex.Pearson'scorrelationcoefficientwas0.734(P<0.001).Conclusions:OurresultssuggestthatADCvaluemaybeusedinmeasurementofcellapoptoticandproliferatingindexesincolorectalcarcinoma.
简介:Objective:Toassessifdiffusion-weightedmagneticresonance(MR)imagingwithoutapparentdiffusioncoefficient(ADC)valuesprovidesaddeddiagnosticvalueincombinationwithconventionalMRimaginginthedetectionandcharacterizationofsmallnodulesincirrhoticliver.Methods:Twoobserversretrospectivelyandindependentlyanalyzed86nodules(≤3cm)certifiedpathologicallyin33patientswithlivercirrhosis,including48hepatocellularcarcinoma(HCC)nodules,13high-gradedysplasticnodules(HDN),10low-gradedysplasticnodules(LDNs)and15otherbenignnodules.AllthesefocalnoduleswereevaluatedwithconventionalMRimages(T1-weighted,T2-weightedanddynamicgadolinium-enhancedimages)andbreath-holddiffusion-weightedimages(DWI)(b=500s/mm2).Thenoduleswereclassifiedbyusingascaleof1-3(1,notseen;3,wellseen)onDWIforqualitativeassessment.Thesesmallnoduleswerecharacterizedbytworadiologists.ADCvaluesweren’tmeasured.ThediagnosticperformanceofthecombinedDWI-conventionalimagesandtheconventionalimagesalonewasevaluatedusingreceiveroperatingcharacteristic(ROC)curves.Theareaunderthecurves(Az),sensitivityandspecificityvaluesforcharacterizingdifferentsmallnoduleswerealsocalculated.Results:Among48HCCnodules,33(68.8%)weregradedas3(wellseen),6(12.5%)weregradedas2(partiallyobscured),and9weren’tseenonDWI.Among13HDNs,therewere3(23.1%)and4(30.8%)gradedas3and2respectively.Five(50%)of10benignnoduleswerepartiallyobscuredandslightlyhyperintense.For86nodules,theaveragediagnosticaccuracyofcombinedDWI-conventionalimageswas82.56%,whichwasincreasedsignificantlycomparedwithconventionalMRimageswith76.17%.ForHCCandHDN,thediagnosticaccuracyofcombinedDWI-conventionalimagesincreasedfrom78.69%to86.07%.Conclusions:Diffusion-weightedMRimagingdoesprovideaddeddiagnosticvalueinthedetectionandcharacterizationofHDNandHCC,anditmaynotbehelpfulforLDNandregenerativenodule(RN)incirrhot
简介:硬件产品:具备学习能力的智能恒温控制器、烟雾报警器,智慧家居生态的先锋。趋势:恒温控制器、烟雾报警器本是静态的产品,但一旦跟别的设备或人产生互动,就会演变成全新的东西。我们还将看到更多新的联网的家居设备,它们将打开充满想象的未来。一家只有两款产品的创业公司竟价值32亿美元!2014年1月14日,谷歌宣布以32亿美元收购美国智能家居公司NestLabs,这是谷歌历史上的第二大收购,仅次于125亿美元收购摩托罗拉的大手笔。与摩托罗拉的江湖地位相比,Nest不过是一家成立仅4年的创业公司,迄今为止也只有智能恒温器Nest,以及烟雾报警器Protect两款产品。在2013年最新一轮融资中,NestLabs估值为8亿美元,相比之下,谷歌给出的价码溢价近300%。Nest究竟有怎样的魔力,让谷歌也为之疯狂?
简介:摘要院针对试验方案评价中指标众多、权重难以确定等问题,引入密切值的评价方法;分析密切值方法的数学原理、处理步骤;给出试验方案密切值评价方法的应用案例;基于VC环境和MFC类库,对密切值评价方法进行软件实现,软件运行稳定,所得结果与理论分析吻合。
简介:院针对传统人工灌溉系统的不足以及灌溉用水效率低的情况,探讨琢值法自动灌溉系统的应用。该系统是按照作物土壤适宜含水率为上、下限,通过蒸发皿的水位变化监控土壤含水率变化,调控电动蝶阀适时开关给灌溉区供水,适时适量灌溉,提高灌水利用率。